Space telegraphy.



PATENTBD APR. '7, 1908.

S. GABOT.

SPACE TELEGRAPHY.

APPLICATION FILED nno.31.1a0e.

ITHEEELE 5 UNITED STATES PATENT OFFICE.

SEWALL CABOT, OF BROOKLINE, MASSACHUSETTS, ASSIGNOR TO TELEGRAPH AND TELEPHONE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

SPACE TE LE GBAPHY.

Specification of Letters Patent.

Patented A n'r'z, 190a.

Application filed December 31, 1906. Serial No. 350,257.

Brookline, in the county of Norfolk and- State of Massachusetts, have invented a new and useful Improvement in Space Telegraphy, of which t e following is a specification.

My invention relates to space telegraphy and more especially to an elevated conductor system which may be employed in a trans mitting or in a receiving system.

My invention consists in a development of or an improvement upon the elevated conductor system described in U. S. Letters Pat-v ent No. 767 ,988, granted to J. S. Stone Aust 16, 1904, to which reference may be had or a more extended explanation of the fundamental principles upon which the present invention 1s based than is necessary to set forth herein.

The object of my invention is to provide an elevated conductor system com rising a laterally extending conducting, s ace having its periphery large compared with its distance above the earth, and having its inner portion cut away or removed, said inner portion of said conducting surface having been found to be ineffective in the reception or transmission of electromagnetic waves.

My invention may best be understood by having reference to the drawing which ac-' companies and forms a part of the present specification and which illustrates, partly in diagram and partly in perspective, one of the several possible embodiments ofmy invention associated with a sonorous or oscillating circuit.

In the drawing, the figure represents a space tele raph transmitting system.

In the gure, V is an elevated conductor consisting of a laterally extending conducting surface, herein shown as formed of wire netting, having its inner,v portion cut away and its erimeter large compared with its distance a ove the earth. The plane of said conductor may be and preferably is substantially parallel to the earth. Said elevated conductor V may be connected to the earth E through the secondary I of the transformer Min any suitable manner and herein is shown as connected to said secondary by three conductors which are joined at symmetrical points with V. The circuit S C I which includes the spark gap S, condenser O in transmitting systems.

and primary I of the transformer M is an oscillating circuit of the kind commonly used It will be understood however that inasmuch as the present invention resides in an elevated conductor system which may be employed in a trans- -mitting or receiving system, the oscillating circuit may be of the type commonly employed in receiving systems, in which case the aforesaid spark ap will of course be omitted and an oscil ation detector associated with the circuit in any suitable manner. It will be understood also that although the oscillating circuit is shown as associated with the elevated conductor system by means of a transformer, I do'not limit myself to such associating means but may couple the two elements of the transmitting or receiving system in any suitable manner.

The natural period of the oscillating circuit should be made equal to the fundamental of the elevated conductor system and means should be employed for rendering the reactance of the said elevated conductor system zero for electrical vibrations of definite although as is now well understood any other suitable means may be employed for this purpose. Preferably the association of the elevated conductor system and the oscillating circuit should be such that the oscillating circuit is rendered the equivalent of a circuit having a single degree of freedom.

It has been found experimentally that the inner portion of the elevated conductor described in the hereinbefore mentioned Letters Patent is ineffective and adds nothing to the efficiency of transmissim or reception. By cutting away said inner portion, I am able to lessen the cost of said conductor and reduce the structural difiicultics connected with erecting and maintaining the same. Also the electrostatic capacity of the elevated conductor system materially is reduced, and this for some purposes is of great advantage. In order further to reduce the difliculties attending the construction and maintenance of the elevated conductor system, I prefer to employ an elevated conductor V which is substantially triangular in shape.

In lieu of the wire netting hereinbeforedescribed, the elevated conductor V may also be formed of parallel wires, preferably of herein described and claimed.

eighty feet above the earth, the separation vdescribedfor the purpose ofmore clearly disclosing my invention.

elevated; conductor V be placed ort feet above the earth,the aforesaid paralle wires.

will beseparated a distance apart of about one foot, and if said conductor be placed of said aralleiwireswill. be about two feet. It he understood that the choice of the two constructions hereinbefore described will depend u on circumstances. Experimental results in 'cate roughly that inthe construction of one of these areas it is of advantage to make the side of the triangle roughly equal to the height that the area is suspended above the earth.

It has been determined experimentally that all the 'advanta es's'et forth in the above mentioned Letters atent for the elevated conductor system therein shown may beob tained, and in fact are obtained in a'greater degree with the elevated conductor system Although I have shown in the accompanyingdrawing a construction preferred by me,

itwill be understood that many other constructions are electrically and 'mechanically equivalent to such preferred. construction and that therefore I do not wish to be limited to the articular embodiment of myinvention which I have illustrated and particularly I claim, a

1. Ina slystem' of space telegraphy, an elevated con uo'to'r system comprising'a laterally extending conducting surface having its inner portion cut away and its perimeter large compared with its distance above the earth, in combination with means for rendering the reactance of said elevated conductor system zero for electrical vibrations of definite frequency.

4. In a system of space telegraphy, an elevated conductor system comprising a laterally extending triangular-shaped conducting surface having its inner portioncut away and its perimeter large compared with its distance above the earth, in combination with means for rendering the-reactance of said elevated conductor system zero for electrical vibrations of definite fr'e uency.

In testimony whereof, l ha ve hereunto subscribed my name this 29 "day of- Dec. 19.06.

I SEWALL' OABOT. Witnesses:

Gno. K. Woonwonrn, E. B. ToMLrNsoN. 

